Tools having a structural metal-matrix composite portion

ABSTRACT

Structural metal-matrix composites (MMC) comprising a foam matrix material infiltrated with a binder material, where the binder material binds the foam matrix material to a structural element of a tool, thereby enhancing three-dimensional reinforcement of the tool. In some instances, the structural element is a portion of a wellbore tool or a bit body, such that portions of such tools or bit bodies are composed of the structural MMC. The foam matrix material may be composed of a metallic foam, a ceramic foam, and any combination thereof.

BACKGROUND

The present disclosure relates to tools having a structural metal-matrixcomposite (MMC) portion and use thereof, and more specifically to toolshaving a structural MMC portion including a metallic and/or ceramic foammatrix material.

Traditional MMCs are composite materials having at least two constituentparts, the first being necessarily metal or metal-based and the secondbeing the same metal in different form (e.g., a foamed metal v. anun-foamed metal), a different metal, or a non-metal material, such as anorganic compound, where the first constituent forms a matrix portion ofthe MMC and the second constituent is dispersed or otherwise embeddedinto the matrix portion, such as to provide structural reinforcementand/or to bind the constituent parts together or to a structuralelement. Greater than two constituent parts may additionally be used toform an MMC, which may be termed hybrid composites. Such MMCs mayinclude structural elements and be used as structural components orportions of various tools or equipment generally requiring erosionresistance, temperature resistance, and/or high impact strength. Forexample, MMCs may be used as part of the automotive industry (e.g., asall or portions of engines, drive shafts, disc brakes, and the like),the aviation industry (e.g., as all or portions of landing gear, and thelike), the electrical industry (e.g., as all or portions of powerelectronic modules, power semiconductor devices, and the like), as wellas other industries.

The oil and gas industry additionally employs a wide variety of wellboretools used in downhole operations that may benefit from the erosionresistance, temperature resistance, and/or high impact strength of anMMC, such as wellbore tools for forming wellbores, wellbore tools usedin completing wellbores that have been drilled, and wellbore tools usedin producing hydrocarbons, such as oil and gas, from the completedwellbores. Wellbore cutting tools, in particular, are frequently used todrill oil and gas wells, geothermal wells and water wells. Wellborecutting tools may include rotary drill bits (e.g., roller cone drillbits and fixed cutter drill bits), reamers, coring bits, under reamers,hole openers, stabilizers, and the like. For example, rotary drill bitsare often formed with a bit body (sometimes referred to in the industryas a composite bit body or a matrix bit body when formed using a MMC),having cutting elements or inserts disposed at select locations aboutthe exterior of the bit body. During drilling, these cutting elementsengage and remove adjacent portions of the subterranean formation.

BRIEF DESCRIPTION OF THE DRAWINGS

The following figures are included to illustrate certain aspects of thedisclosure, and should not be viewed as exclusive. The subject matterdisclosed is capable of considerable modifications, alterations,combinations, and equivalents in form and function, as will occur tothose skilled in the art and having the benefit of this disclosure.

FIG. 1 is a scanning electron microscope image of a closed celledmetallic foam matrix material composed of nickel, prepared according toone or more examples described herein.

FIG. 2 is a cross-sectional view showing one example of a drill bithaving a bit body with at least one structural MMC portion in accordancewith the teachings of the present disclosure.

FIG. 3 is an isometric view of the drill bit of FIG. 1.

FIG. 4 is an end view showing one example of a mold assembly for use informing a bit body in accordance with the teachings of the presentdisclosure.

FIG. 5 is a cross-sectional view showing one example of a mold assemblyfor use in forming a bit body in accordance with the teachings of thepresent disclosure.

FIG. 6 is a cross-sectional view showing one example of a drill bit inaccordance with the teachings of the present disclosure.

FIG. 7 is a cross-sectional view showing one example of a drill bit inaccordance with the teachings of the present disclosure.

FIG. 8 is a cross-sectional view showing one example of a drill bit inaccordance with the teachings of the present disclosure.

FIG. 9 is a cross-sectional view showing one example of a matrix drillbit in accordance with the teachings of the present disclosure.

FIG. 10 is a schematic drawing showing one example of a drillingassembly suitable for use in conjunction with the drill bits of thepresent disclosure.

DETAILED DESCRIPTION

The present disclosure relates to tools having a structural metal-matrixcomposite (MMC) portion and use thereof, and more specifically to toolshaving a structural MMC portion including a metal-based (i.e., metallicand/or ceramic) foam matrix material, a binder material, and astructural element. These portions are distinguishable from other typesof hard MMC portions that do not contain metallic and/or ceramic foammatrix material and that do not contain a structural element.

As used herein, the term “structural MMC,” and grammatical variantsthereof, for use in the examples of the present disclosure includes atleast a metal-based (i.e., metal, ceramic, and any combination thereof)foam matrix material, a binder material, and a structural element. Theterm “foam matrix material,” and grammatical variants thereof, as usedherein refers to an inflexible material having a cellular structure ofsolid metal and/or ceramic capable of having a binder material andoptional reinforcement (i.e., strengthening) material dispersed orotherwise embedded within the cellular structure. As used herein, theterm “binder material,” and grammatical variants thereof, refers to amaterial dispersed or otherwise embedded within a foam matrix materialthat is capable of binding the foam matrix material to a structuralelement. The binder material may, in some instances, additionallyprovide structural reinforcement to and/or alter the physical properties(e.g., wear resistance, friction coefficient, thermal conductivity, andthe like) of the foam matrix material. The term “structural element,”and grammatical variants thereof, as used herein refers to any portionof a tool providing a structural form thereto for a specificapplication, such as a portion of a wellbore tool (e.g., a drill bit, aleg of a drill bit, and the like). For example, the structural elementmay be a mandrel, a leg, a core, and insert, and/or a displacementstructural element meant to supply a void space to a particular tool,and the like, without departing from the scope of the presentdisclosure.

The teachings of this disclosure may be applied to any tool that can beformed at least partially of structural MMC materials in accordance withthe instant disclosure, including tools in any industry, such as thosedescribed above. By way of example, the teachings of the presentdisclosure may be illustrated with reference to wellbore tools thatexperience wear during contact with a wellbore or other downhole devicesduring downhole operations. Such wellbore tools may include tools fordrilling wells, completing wells, and producing hydrocarbons from wells.Examples of such tools may include, but are not limited to, cuttingtools, such as drill bits, reamers, stabilizers, and coring bits;drilling tools such as rotary steerable devices, mud motors; and othertools used downhole such as window mills, packers, tool joints, andother wear-prone tools. Even more particularly, examples of theteachings of the present disclosure may be illustrated with reference toa drill bit having a bit body with at least one portion thereof formedby a structural MMC comprising a metallic and/or ceramic foam matrixmaterial infiltrated with a binder material, and a structural element.It is to be appreciated, nevertheless, that the examples describedherein are non-limiting and the structural MMCs described herein areapplicable to any tool that can be formed at least partially therefrom,without departing from the scope of the present disclosure.

Traditional composite materials may be formed by placing loosereinforcement material in particulate powder form into a mold andinfiltrating the particulate powder matrix material with a reinforcementand/or binder material, followed by solidification. The structural MMCsdescribed herein may exhibit comparatively enhanced mechanicalproperties, even at low volume fractions, by utilizing a metallic and/orceramic foam matrix material (collectively simply “foam matrixmaterial”). The foam matrix material may be composed of a metallicand/or ceramic material and may be used in lieu of traditionalparticulate powder matrix material. Alternatively, the foam matrixmaterial described herein may be used in combination with an optionalreinforcement material, without departing from the scope of the presentdisclosure (referred to herein as “optional reinforcement material”).The term “optional reinforcement material,” and grammatical variantsthereof, refers to herein as a material that is dispersed or otherwiseembedded within the foam matrix material of the instant disclosure toprovide structural reinforcement and/or alteration of physicalproperties to the foam matrix material, and may be in particulate(encompassing particles, fibers, and powder forms). In any examplesdescribed herein, the foam matrix material may be used in combinationwith optional reinforcement material(s) (e.g., optional particulatereinforcement material(s)), without departing from the scope of thepresent disclosure.

The foam matrix material described herein provides a structurally rigid,three-dimensional reinforcement that may behave in a similar nature tobundled fiber material. However, the foam matrix material is notdesigned using aspect ratios and length (as would be true for bundledfiber material), but instead based on cell type (e.g., open cell orclosed cell) and cell size. The cell type and the cell size of the foammatrix material defines the type of structure it is able to provide to astructural MMC, including structural MMCs forming all or a portion of atool, such as a wellbore tool. The rigid (inflexible), three-dimensionalstructure of the foam matrix materials described herein additionallyphysically support themselves and can be shaped as needed (and holdtheir shape) to provide desired capabilities for particular tools (e.g.,drill bits). Indeed, the foam matrix materials described herein may beshaped (e.g., machine shaped) into various shapes to easily fit thedesired shape of the structural MMC, including any all or a portion of atool or wellbore tool it forms. Accordingly, the shape of the foammatrix material can be customized.

The structural MMCs of the present disclosure may be formed by placing afoam matrix material in a region of a mold comprising a structuralelement (e.g., a tool mold, such as a wellbore tool mold). The foammatrix material is then infiltrated with a binder material as a resultof heating the mold. The mold is thereafter cooled, along with the foammatrix material and the binder material.

More specifically, and as discussed in greater detail below, the moldmay initially have one or more displacement structural elements placedat strategic locations corresponding to the desired exterior and/orinterior portions of a desired tool, for example. Thereafter, a foammatrix material is placed in the mold. The foam matrix material for usein the present disclosure is at least a metallic and/or ceramic foammatrix material and may optionally include optional reinforcementmaterial (e.g., tungsten carbide particulates). Next, a binder materialis placed in the mold, which may remain atop the foam matrix material.The mold and its contents are then heated, and when the temperatureexceeds the melting point of the binder material, it infiltrates (orflows into) the foam matrix material and contacts the interiordisplacement structural elements. The mold and its contents (i.e., thefoam matrix material, the binder material, any optional reinforcementmaterial, and the structural element(s)) are then cooled to form theresultant structural MMC.

The foam matrix material may be placed in the mold in a pre-formedconfiguration (i.e., in a solid configuration, which may be preferred)or may be formed through the process of forming the structural MMC,depending on the binder material selected. The foam matrix material maybe formed by introducing gas bubbles into a molten form of the materialused to form the foam matrix material. The gas bubbles may be formed byinjecting gas into the molten material, causing an in situ gasformation, or causing precipitation of gas previously dissolved in themolten material. Alternatively, the foam matrix material may be machinedfrom the solid material selected to form the foam matrix material.

Advantageously, the rigid, three-dimensional structure of the foammatrix material may allow increased control over the structure and anyreinforcement of the structural MMC. For example, in traditional MMCs,the use of loose matrix materials (e.g., particulates (which includepowders, particles, and fibers herein)) can result in irregularities ofa reinforcement structure, such as due to non-uniform physicalproperties, anisotrophic properties (e.g., in the case of fibers thatmay tend to “lie down” due to such properties), vibrational forces,gravitational forces, non-uniform infiltration, and the like. Suchirregularities may cause areas of the resultant MMC to have variableproperties throughout (e.g., areas of concentrated matrix material,areas of concentrated binder material, and the like). The use of thefoam matrix material described herein, however, may provide a porousstructure to permit flow of the binder material and any additionaloptional reinforcement material, thus providing better and morecontrolled placement therein. Additionally, where optional reinforcementmaterial such those that are fiber-shaped are used, the fiber-shapedmaterial may be held in place within the foam matrix material, while thepores allow the flow of any optional particulate reinforcement materialand the binder material into the structure of the foam matrix material.After solidification of the structural MMC, it may be used to providereinforcement or toughness to a portion of a tool (e.g., a bit body),depending on the composition of the foam matrix material and theremaining components of the structural MMC, such as the binder materialand any optional reinforcement material.

The foam matrix material described herein comprises a metal, a ceramic,or a combination of a metal and a ceramic and has a cellular structure,as defined above. The cellular structure of the foam matrix material maybe an open cell or closed cell, which may be utilized to alter theproperties of the structural MMC. A “closed cell” foam matrix material,and grammatical variants thereof, refers to a foam having sealed pores(i.e., the pores are sealed from adjacent pores). Differently, an “opencell” foam matrix material, and grammatical variants thereof, refers toa foam having an interconnected network of pores (i.e., the pores areopen to adjacent pores). FIG. 1 is a scanning electron microscope imageof an open cell metallic foam matrix material composed of nickel,prepared according to one or more examples described herein. Closed cellconfigurations may allow for localized areas of toughness within thestructural MMC, while open cell configurations lend to structuralreinforcement that may have improved material properties, such ascompression, tensile strength, and/or fracture toughness.

The size of the cell, whether open or closed, in a foam matrix materialas described herein may additionally be controlled or otherwise variedto adjust the properties of a resultant structural MMC. For example, thecell size in an open celled foam matrix material may allow control overhow much reinforcement is present in the structural MMC (e.g., generallythe larger the openings, the less reinforcement, and vice versa).Furthermore, the foam matrix material may be customized based on theinclusion of additional optional reinforcement materials, their type,their shape, and/or their amount. In other examples, small cell size ina foam matrix material may be used to prevent or hinder optionalparticulate reinforcement material in certain areas, thus resulting in abinder-rich zone that may impart increased toughness and/or crackresistance to certain portions of the structural MMC. Similarly, smallcell size in the foam matrix material may be used to prevent or hinderother optional reinforcement materials from entering into the foammatrix material, additionally resulting in a binder-rich zone to impartsimilar qualities to the structural MMC. That is, the foam matrixmaterial may act as a filter to allow certain materials (e.g., bindermaterials, optional reinforcement materials, and the like, andcombinations thereof) to be layered or otherwise varied relative to eachother and/or to achieve specified configurations and compositions, thusimparting specific qualities to the structural MMC.

Alternatively or additionally to cell type and cell size, cell shape ofthe foam matrix material described herein may be used to impart certainqualities to the structural MMCs. For example, cell shape of the poresof a foam matrix material may be selected or otherwise designed topreferentially allow certain additional optional reinforcement materialshaving particular morphologies to pass through while precluding othermorphologies. For instance, spherical or substantially spherical cellshapes may permit similarly shaped optional reinforcement materials topass, whereas optional reinforcement materials of other shapes (e.g.,irregular, plate-like, and the like) may be precluded. Use of cellshapes may thus result in certain properties, such as more dense packingor even distribution of any optional reinforcement material. Moreover,such packing or distribution of any optional reinforcement material mayresult in non-uniform or uniform infiltration of binder material,additionally allowing customization of the properties of the subsequentstructural MMC.

The foam matrix materials described herein may be composed of any metal,ceramic, or combination thereof capable of being formed into a foam andused to form a structural MMC, as defined herein. Selection of suchmaterials may depend on the use of the structural MMC, such as the toolor portion of the tool that it is used to form. For example, if thestructural MMC forms a portion of a wellbore tool, the foam matrixmaterial(s) should be selected for use in a downhole environment (e.g.,downhole temperatures, downhole pressures, downhole friction forces, andthe like).

The melting point of the foam matrix material may be selected to have amelting point greater than or less than the melting point of the bindermaterial, without departing from the scope of the present disclosure. Inany or all specific examples described herein, the composition of thefoam matrix material may be selected to have a melting point greaterthan the melting point of the binder material(s), discussed below,selected to form the structural MMC, which may be greater than 1000° C.in some instances. The term “melting point,” and grammatical variantsthereof, as used herein, refers to the temperature at which a solid(e.g., the foam matrix material) melts. In an example, the compositionof the foam matrix material may be selected to have a melting point inthe range of 1000° C. to 4000° C., encompassing any value and subsettherebetween. For example, the composition of the foam matrix materialmay be selected to have a melting point of 1000° C. to 1500° C., or1500° C. to 2000° C., or 2000° C. to 2500° C., or 2500° C. to 3000° C.,or 3000° C. to 3500° C., or 3500° C. to 4000° C., or 1500° C. to 3500°C., or 2000° C. to 3000° C., encompassing any value and subsettherebetween. Alternatively or additionally, the composition of the foammatrix material may be selected to have an oxidation temperature for thegiven atmospheric conditions that is greater than the melting point ofthe binder material(s).

In one or all examples, the foam matrix material described herein mayhave a composition that bonds with the binder material(s), so that anincreased amount of thermal and mechanic stresses (or loads) can betransferred to the foam matrix material. Further, a composition thatbonds with the binder material(s) may be less likely to pull out fromthe binder material as a crack potentially propagates in the structuralMMC. That is, the binder material serves to bond the foam matrixmaterial to one or more structural elements, and may additionally bondto the foam matrix material itself, without departing from the scope ofthe present disclosure.

Additionally, in one or all examples, the composition of the foam matrixmaterial may endure temperatures and pressures experienced when forminga structurally MMC, as described in greater detail below, with little tono alloying with the binder material(s) or oxidation. However, in someinstances, the atmospheric conditions may be changed (e.g., reducedoxygen content achieved via reduced pressures or gas purge) to mitigateoxidation of the foam matrix material to allow for a composition thatmay not be suitable for use in standard atmospheric oxygenconcentrations.

In some instances, the foam matrix material is a metallic foam composedof a metal (e.g., an alkali metal, an alkaline metal, a transitionmetal, a post-transition metal, a lanthanide, an actinide), a metalalloy, a metal carbide, a superalloy, and the like, and any combinationthereof. Specific examples of metallic foams suitable for use inconjunction as the foam matrix material described herein may include,but are not limited to, aluminum, iron, cadmium, cobalt, copper, carbon,vitreous carbon, gold, lead, molybdenum, nickel, niobium, rhenium,silicon, silver, tantalum, tin, titanium, tungsten, zinc, zirconium,copper-aluminum alloy, hafnium-carbide alloy, an iron alloy (e.g.,iron-chromium alloy, iron-chromium-aluminum alloy, and the like),lanthanated molybdenum alloy, a nickel alloy (e.g.,nickel-chromium-aluminum alloy, nickel-chromium alloy, nickel-ironalloy, nickel-iron-chromium alloy, nickel-manganese-gallium alloy,nickel-copper-chromium alloy, and the like), tungsten-nickel alloy,N-155 alloy, steel, stainless steel, austenitic stainless steel,ferritic steel, martensitic steel, a chromium alloy, boron carbide,silicon carbide, tantalum carbide, zinc carbide, zirconium carbide,molybdenum carbide, titanium carbide, niobium carbide, chromium carbide,vanadium carbide, iron, carbide, tungsten carbide, nickel-basedsuperalloys, silicon nitride carbide, graphite, and the like, and anycombination thereof.

Examples of suitable commercially available superalloys for use informing the metallic foam matrix materials described herein may include,but are not limited to, INCONEL® alloys (austenitic nickel-chromiumcontaining superalloys, available from Special Metals Corporation),WASPALOYS® (austenitic nickel-based superalloys), RENE® alloys(nickel-chrome containing alloys, available from Altemp Alloys, Inc.),HAYNES® alloys (nickel-chromium containing superalloys, available fromHaynes International), INCOLOY® alloys (iron-nickel containingsuperalloys, available from Mega Mex), MP98T (a nickel-copper-chromiumsuperalloy, available from SPS Technologies), TMS alloys, CMSX® alloys(nickel-based superalloys, available from C-M Group), and the like, andany combination thereof.

In some instances, the foam matrix material is a ceramic foam composedof an oxide ceramic, a boride ceramic, a nitride ceramic, a silicateceramic, a carbide ceramic, diamond (e.g., natural diamond, syntheticdiamond, and the like), and the like, and any combination thereof.Specific examples of ceramic foams suitable for use in conjunction asthe foam matrix material described herein may include, but are notlimited to, silicon oxide, silicon dioxide, aluminum oxide, aluminumtitanate, beryllium oxide, zirconium oxide, magnesium oxide, titaniumdioxide, lead zirconium titanate, titanium diboride, zirconium diboride,hafnium diboride, silicon nitride, aluminum nitride, boron nitride,titanium nitride, zirconium nitride, vanadium nitride, niobium nitride,tantalum nitride, hafnium nitride, porcelain, steatite, cordierite,mullite, and the like, and any combination thereof.

Combinations of the aforementioned metallic foams and ceramic foams mayadditionally be used to compose the foam matrix materials describedherein, without departing from the scope of the present disclosure.Accordingly, the foam matrix materials of the present disclosure canutilize desirable benefits from one or more of the metallic and/orceramic foams in combination.

The selection of the particular foam matrix material may depend on anumber of factors, including those described above. The particular foammatrix material may be selected based on its particular eventual use ina structural MMC (including the type and use of any tool in which it isused), the selected binder material(s), any optional reinforcementmaterial, and the like.

For example, the foam matrix material may be selected such that it willmelt into, dissolve into, diffuse into, or react with the selectedbinder material(s) during infiltration of the foam matrix material withthe binder material, as described below, thereby forming a networkedductile phase. As used herein, the term “networked ductile phase,” andgrammatical variants thereof, refers to a network of material that hasan ability to absorb an impact or shock load with a lower propensity tofracture due to the networked material structure. Such networked ductilephase may possess pliability and/or flexibility, which may then imparttoughness to the resultant structural MMC.

Alternatively, the foam matrix material may be selected such that itwill react with the selected binder material(s) during infiltration ofthe foam matrix material with the binder material, thereby forming anintermetallic phase. As used herein, the term “intermetallic phase”refers to one or more phases comprising two elements in a covalent orionic bond with a different crystal structure than that of thesurrounding phase. Such intermetallic phase may possess high strengthand/or stiffness, which may then impart strengthening, stiffening,and/or erosion resistance to the resultant structural MMC (as opposed totoughness, for example). Indeed, for example, when the structural MMCforms a portion of a wellbore tool, such as a drill bit, and is locatedat or near the surface of the drill bit (e.g., the bit body), stiffnessof the structural MMC (e.g., by virtue of the intermetallic phase) toenhance erosion resistance of the drill bit. Stiffness may further beenhanced by including additional large particle sized optionalreinforcement material within the foam matrix material.

Alternatively, the foam matrix material and binder material(s) may beselected such that they will dissolve into or react with each otherduring infiltration, such that after infiltration the shape of thestructural MMC resembles tetrahedral molecular geometry comprising sixstraight edges, where the straight edges are evenly spaced andindependent of one another. The tetrahedral geometry may impart highbond strength to the structural MMC. This geometry may be also beenhanced when the outer surface of the foam matrix material is designedto be thick. This geometry may provide an enhanced combination ofstrength and stiffness because the foam matrix material impartsstrengthening (e.g., stiffness, ultimate tensile strength, and the like)in discrete, independent modules (which may or may not be themselvesindividual tetrahedrons) and, thus, may be less prone or not prone tocrack propagation and/or crack failure. Any groupings forming thetetrahedral geometry may form the shape of the structural MMC describedherein, without departing from the scope of the present disclosure.

Accordingly, the shape of the foam matrix material may be customized—thecell type, size, and shape of the foam matrix material may becustomized; and/or the toughness, stiffness, or other qualities of thefoam matrix material may be customized (e.g., due to the selection ofcertain foam matrix material types(s)). The inclusion of optionalreinforcement material and its distribution within the foam matrixmaterial, in combination with the type and reactivity of the selectedbinder material(s) allows further customization. Thus, the resultantstructural MMC may have portions that are tough, portions that arestiff, portions that are brittle, portions that are erosion resistant,and the like by strategically forming the structural MMC. Moreover, suchcustomization allows prudent use of certain components or compositionalelements that may be expensive or in short supply, as these componentsand others can be selectively included in the structural MMC.

In any or all examples, the selected foam matrix material may itself befurther treated to alter the material properties of the selected foammaterial. For example, the selected foam material may be a metallic foamcomposed of a metal alloy, and the metal alloy may be itself heattreated such that increased strength or stiffness is imparted prior toforming it into the foam matrix material. Alternatively or in additionto, the material properties of the foam material selected for formingthe foam matrix material can be altered during the infiltration process(e.g., to impart increased strength or stiffness). That is, the selectedfoam material may be a metal alloy that is selected (or formulated) suchthat the infiltration process alone during forming the structural MMCimparts the requisite heat input to alter the properties of the metalalloy, and thus the structural MMC, such as by causing precipitationhardening throughout the foam material forming the foam matrix material.Accordingly, no additional manufacturing steps would be needed inaddition to the manufacture of the structural MMC alone to alter theproperties of the foam matrix material. Alternatively, the selected foammaterial forming the foam matrix material may be a ceramic material thatcan be pretreated to improve fracture resistance or bonding with theselected binder material(s).

In any or all examples of the structural MMCs described herein, anoptional reinforcement material may be used in combination with theceramic and/or metallic foam matrix materials and/or the binder materialto further customize the structural MMC (e.g., to provide additionalreinforcement). Such optional reinforcement materials may include, butare not limited to, reinforcing particulates, encompassing powders,particles, and fibers, and the like, and any combination thereof. Theseoptional reinforcement materials may be dispersed or embedded in thefoam matrix material prior to the step of infiltration with the bindermaterial(s) or may be directly included in the binder material(s) andplaced into the foam matrix material during the infiltration process(e.g., with the binder material(s)), without departing from the scope ofthe present disclosure.

As used herein, the “reinforcing particulates” have a shape such thatthey are substantially spherical, polygonal, or fibrous in shape. Asused herein, the term “substantially spherical,” and grammaticalvariants thereof, refers to a material that has a morphology thatincludes spherical geometry and elliptic geometry, including oblongspheres, ovoids, ellipsoids, capsules, and the like, and hybridsthereof. The term “polygonal,” and grammatical variants thereof, as usedherein, refers to shapes having at least two straight sides and angles.Examples of polygonal shapes may include, but are not limited to, acube, cone, pyramid, cylinder, rectangular prism, cuboid, triangularprism, icosahedron, dodecahedron, octahedron, pentagonal prism,hexagonal prism, hexagonal pyramid, and the like, and hybrids thereof.As used herein, the term “fibrous,” and grammatical variants thereof,refers to fiber-shaped substances having aspect ratios of greater than2, or in the range of 2 to 500, encompassing any value and subsettherebetween. For example, the fibrous reinforcing particles may have anaspect ratio of 2 to 50, or 50 to 100, or 100 to 200, or 200 to 300, or300 to 400, or 400 to 500, or 50 to 450, or 100 to 400, or 150 to 350,or 200 to 300, encompassing any value and subset therebetween.Accordingly, “fibrous” shapes encompass fibers, rods, wires, dog bones,whiskers, ribbons, discs, wafers, flakes, rings, and the like, andhybrids thereof. As used herein, the term “dog bone” refers to anelongated structure like a fiber, whisker, or rod where thecross-sectional area at or near the ends of the structure are greaterthan a cross-sectional area therebetween. As used herein, the “aspectratio” refers to the ratio of the longest dimension to the thickness.

A collection of fiber-shaped reinforcing particulates may be arranged toform a 2-dimensional or 3-dimensional structure (e.g., an oriented wool,a disoriented wool, or a mesh). As used herein, the term “oriented wool”refers to an entangled mass of fibers where at least 90% of the fibersare oriented within 25° of each other (e.g., steel wool), which may be aresult of the manufacturing process, entanglement method, or anorienting process (e.g., stretching a disoriented wool). As used herein,the term “disoriented wool” is an entangled mass of continuous fibersthat are less oriented than an oriented wool. As used herein, the term“wool” encompasses both oriented wools and disoriented wools.

The size of the reinforcing particulates may be such that they have aunit mesh particle size in the range of 0.05 micrometer (μm) to 2000 μm,encompassing any value and subset therebetween. Accordingly, the term“reinforcing particulates” encompasses powder forms. For example, thesize of the reinforcing particulates may have a unit mesh size of 0.05μm to 5 μm, or 5 μm to 400 μm, or 400 μm to 8000 μm, or 800 μm to 1200μm, or 1200 μm to 1600 μm, or 1600 μm to 2000 μm, or 400 μm to 1600 μm,or 800 μm to 1200 μm, encompassing any value and subset therebetween. Asused herein, the term “unit mesh particle size” or simply “unit meshsize” refers to a size of an object (e.g., a particulate) that is ableto pass through a square area having each side thereof equal to thespecified numerical value provided herein. One skilled in the art wouldrecognize that the length of the any fiber-shaped reinforcingparticulate will depend on their unit mesh size diameter.

The optional reinforcing particulates may be composed of any materialdescribed above with reference to the metallic foam and/or ceramic foamsfor use in forming the foam matrix materials described herein and belowwith reference to the binder materials. The optional reinforcementparticulates may additionally be composed of sand, glass materials,polymer materials (e.g., polystyrene, polyethylene, etc.), nut shellpieces, wood, cements (e.g., Portland cements), fly ash, carbon blackpowder, silica, alumina, alumino-silicates, fumed carbon, carbon black,graphite, mica, titanium dioxide, barite, meta-silicate, calciumsilicate, calcium carbonate, dolomite, nepheline syenite, feldspar,pumice, volcanic material, kaolin, talc, zirconia, boron, shale, clay,sandstone, mineral carbonates, mineral oxide, iron oxide, formationminerals, any of the aforementioned mixed with a resin to form curedresinous particulates, and any combination thereof.

Additionally, the optional reinforcing particulates may be selected tohave one, more than one, or all of the various characteristics discussedabove with reference to the foam matrix material (e.g., a melting pointabove the melting point of the binder material; an oxidation temperaturefor the given atmospheric conditions that is greater than the meltingpoint of the binder material(s); a material that melts into, dissolvesinto, diffuses into, or reacts with the binder material duringinfiltration; and the like; and any combination thereof).

Binder material compositions may be any material suitable for use informing a structural MMC in accordance with the present disclosure, andmay be the same material in different form (i.e., a non-foam) or adifferent material selected for forming the foam matrix material,provided that it is able to at least bond the foam matrix material andthe structural element. As an example, the binder material may be nickeland the foam matrix material may also be nickel. Accordingly, thematerials available for forming the binder material and the foam matrixmaterial may be identical, without departing from the scope of thepresent disclosure. In some, but not all examples of the instantdisclosure, the composition of the foam matrix materials may be chosento have a melting point equal to or greater than the melting point ofthe binder material for a particular structural MMC.

Examples of suitable binder materials for use in the present disclosuremay include, but are not limited to, copper, nickel, cobalt, iron,aluminum, molybdenum, chromium, manganese, tin, zinc, lead, silicon,tungsten, boron, phosphorous, gold, silver, palladium, indium, anymixture thereof, any alloy thereof, and any combination thereof.Additional specific examples of binder materials may include, but arenot limited to, copper-phosphorus, copper-phosphorous-silver,copper-manganese-phosphorous, copper-nickel, copper-manganese-nickel,copper-manganese-zinc, copper-manganese-nickel-zinc,copper-nickel-indium, copper-tin-manganese-nickel,copper-tin-manganese-nickel-iron, gold-nickel, gold-palladium-nickel,gold-copper-nickel, silver-copper-zinc-nickel, silver-manganese,silver-copper-zinc-cadmium, silver-copper-tin,cobalt-silicon-chromium-nickel-tungsten,cobalt-silicon-chromium-nickel-tungsten-boron,manganese-nickel-cobalt-boron, nickel-silicon-chromium,nickel-chromium-silicon-manganese, nickel-chromium-silicon,nickel-silicon-boron, nickel-silicon-chromium-boron-iron,nickel-phosphorus, nickel-manganese, copper-aluminum,copper-aluminum-nickel, copper-aluminum-nickel-iron,copper-aluminum-nickel-zinc-tin-iron, and the like, and any combinationthereof. Examples of commercially available binder materials mayinclude, but are not limited to, VIRGIN™ Binder material 453D(copper-manganese-nickel-zinc, available from Belmont Metals, Inc.);copper-tin-manganese-nickel and copper-tin-manganese-nickel-iron grades516, 519, 523, 512, 518, and 520 available from ATI Firth Sterling; andany combination thereof. Binder materials comprising copper, nickel,manganese, zinc, and any combination thereof, alone or with othermaterials may be preferred.

By way of non-limiting example, FIGS. 2-9 provide examples ofimplementing the structural MMCs comprising a metallic and/or ceramicfoam matrix material infiltrated with a binder material(s), andincluding a structural element, described herein in drill bits. Oneskilled in the art will recognize how to adapt these teachings to othertools or wellbore tools, including, but not limited to, all thosementioned herein, or portions thereof.

FIG. 2 is a cross-sectional view showing one example of a drill bit 20formed with a bit body 50 that has a structural MMC portion 131comprising a foam matrix material, a binder material infiltrated throughthe foam matrix material, and one or more structural elements. As usedherein, the term “drill bit” encompasses rotary drag bits, drag bits,fixed cutter drill bits, and any other drill bits having a bit bodycapable of incorporating the teachings of the present disclosure (i.e.,capable of incorporating a structural MMC).

As shown in FIG. 2, the drill bit 20 may include a structural elementmetal shank 30 with a structural element metal blank 36 securelyattached thereto (e.g., at weld location 39). The metal blank 36 mayextend into the bit body 50. The metal shank 30 may have a threadedconnection 34 distal to the metal blank 36. The metal shank 30 and metalblank 36 are generally cylindrical structural elements that at leastpartially define corresponding fluid cavities 32 that fluidlycommunicate with each other. The fluid cavity 32 of the metal blank 36may further extend into the bit body 50. At least one structural elementflow passageway (shown as two flow passageways 42 and 44) may extendfrom the fluid cavity 32 to the exterior portions of the bit body 50.Structural element nozzle openings 54 may be defined at the ends of theflow passageways 42 and 44 at the exterior portions of the bit body 50.

A plurality of indentations or pockets 58 may be formed at the exteriorportions of the bit body 50 and may be shaped to receive correspondingcutting elements (shown in FIG. 3).

Regarding crack propagation in a bit body 50, in some instances, cracksmay originate at or near the nozzle openings 54 and propagate up flowpassageways 42 and 44 in the direction of arrows A and B, respectively.As described further herein, the stress (or load) of the fracture maytransfer to the structural MMC, and more particularly to the foam matrixmaterial described herein, and mitigate crack propagation. Therefore,strengthening of the foam matrix material that is at a locationnon-parallel to the crack propagation direction provide some degree ofload transfer and mitigation of crack propagation, which may be achievedusing the foam shape and size; cell type, size, and shape; foam materialselection; and the like, as described above. In some instances, the foammatrix material (or a portion thereof) is strengthened at a locationsubstantially perpendicular (e.g., within 25° of perpendicular) to thecrack propagation direction to maximize stress transfer and minimizecrack propagation.

FIG. 3 is an isometric view showing one example of a drill bit 20 thatmay be formed with the bit body 50 formed by a structural MMC comprisinga foam matrix material, a binder material infiltrated through the foammatrix material, and a plurality of structural elements in accordancewith the teachings of the present disclosure. As illustrated, the drillbit 20 includes the metal blank 36 and the metal shank 30, as generallydescribed above with reference to. FIG. 2. The bit body 50 includes aplurality of cutter blades 52 formed on the exterior of the bit body 50.Cutter blades 52 may be spaced from each other on the exterior of thestructural MMC bit body 50 to form fluid flow paths or junk slots 62therebetween.

As illustrated, the plurality of pockets 58 may be formed in the cutterblades 52 at selected locations to receive corresponding cuttingelements 60 (also known as cutting inserts), securely mounted (e.g., viabrazing) in positions oriented to engage and remove adjacent portions ofa subterranean formation during drilling operations. More particularly,the cutting elements 60 may scrape and gouge formation materials fromthe bottom and sides of a wellbore during rotation of the drill bit 20by an attached drill string (not shown). For some applications, varioustypes of polycrystalline diamond compact (PDC) cutters may be used ascutting elements 60. A drill bit having such PDC cutters may sometimesbe referred to as a “PDC bit”.

A nozzle 56 may be disposed in each nozzle opening 54. For example,nozzles 56 may be described or otherwise characterized as“interchangeable” nozzles.

Regarding crack propagation in a bit body 50, in some instances, cracksmay develop in the blades 52 from any direction due to impact and torqueexperienced during drilling. Because the cracks may originate from alldirections, the foam matrix material of the structural MMC may beuniformly strengthened using one or more methods described above,including the inclusion of additional reinforcing particulates, toreinforce the blades 52.

A wide variety of molds may be used to form a structural MMC bit bodyand associated drill bit in accordance with the teachings of the presentdisclosure.

FIG. 4 is an end view showing one example of a mold assembly 100 for usein forming a bit body incorporating teachings of the present disclosure.A plurality of structural element mold inserts 106 may be placed withina cavity 104 defined by or otherwise provided within the mold assembly100. The mold inserts 106 may be used to form the respective pockets inblades of the bit body. The location of mold inserts 106 in cavity 104corresponds with desired locations for installing the cutting elementsin the associated blades. Mold inserts 106 may be formed from varioustypes of material such as, but not limited to, consolidated sand andgraphite, or any material described herein with reference to the foammatrix material, the binder material, and the optional reinforcementmaterial.

FIG. 5 is a cross-sectional view of the mold assembly 100 of FIG. 4 thatmay be used in forming a bit body incorporating teachings of the presentdisclosure. The mold assembly 100 may include several components such asmold 102, a gauge ring or connector ring 110, and a funnel 120. Mold102, gauge ring 110, and funnel 120 may be formed from any materialdescribed herein with reference to the foam matrix material, the bindermaterial, such as from graphite. Various techniques may be used tomanufacture the mold assembly 100 including, but not limited to,machining a graphite blank to produce the mold assembly 100 with theassociated cavity 104 having a negative profile or a reverse profile ofdesired exterior features for a resulting bit body. For example, thecavity 104 may have a negative profile that corresponds with theexterior profile or configuration of the blades 52 and the junk slots 62formed therebetween, as shown in FIGS. 2-3.

Various types of temporary structural element displacement materials maybe installed within cavity 104, depending upon the desired configurationof a resulting drill bit. Additional structural element mold inserts(not expressly shown) may be formed from various materials (e.g.,consolidated sand and/or graphite) may be disposed within cavity 104.Such mold inserts may have configurations corresponding to the desiredexterior features of the drill bit (e.g., junk slots).

Displacement materials (e.g., consolidated sand) may be installed withinthe mold assembly 100 at desired locations to form the desired exteriorfeatures of the drill bit (e.g., the fluid cavity and the flowpassageways). Such structural element displacement materials may havevarious configurations. For example, the orientation and configurationof the consolidated sand legs 142 and 144 may be selected to correspondwith desired locations and configurations of associated flow passagewaysand their respective nozzle openings. The consolidated sand legs 142 and144 may be coupled to threaded receptacles (not expressly shown) forforming the threads of the nozzle openings that couple the respectivenozzles thereto.

Other structural elements, such as a relatively large, generallycylindrically-shaped consolidated sand core 150 may be placed on thelegs 142 and 144. Core 150 and legs 142 and 144 may be sometimesdescribed as having the shape of a “crow's foot.” Core 150 may also bereferred to as a “stalk.” The number of legs 142 and 144 extending fromcore 150 will depend upon the desired number of flow passageways andcorresponding nozzle openings in a resulting bit body. The legs 142 and144 and the core 150 may also be formed from graphite or other suitablematerials, including any of those described herein with reference to thefoam matrix material(s), the binder material(s), and the optionalreinforcement material(s).

After desired displacement materials, including for example core 150 andlegs 142 and 144, have been installed within the mold assembly 100, thefoam matrix material 130 may then be placed within or otherwiseintroduced into the mold assembly 100. In an example, the foam matrixmaterial described herein may be placed in a desired area or portion ofthe mold assembly 100 and optional reinforcement material (e.g.,particulate powder of tungsten carbide) added around the placed foammatrix material. Alternatively, the foam matrix material may haveoptional reinforcement material(s) (e.g., particulate powder of tungstencarbide) mixed therein. In another example, the foam matrix materialdescribed herein may be formed into a specific shape for use in formingthe solidified or hardened structural MMC, and if present, optionalreinforcement material (e.g., particulate powder of tungsten carbide)may be dispersed or otherwise embedded therein. For example, the foammatrix material as a whole may be spiral-shaped, a mesh, or an orientedwool and placed around the legs 142 and 144, which, with reference toFIG. 2, may be oriented to mitigate crack propagation up flowpassageways 42 and 44 in the direction of arrows A and B, respectively.In another example, the foam matrix material may be formed to have cellsizes allowing sufficient interstitial spacing for optionalreinforcement material particles to flow therethrough. In someinstances, the foam matrix material may be fabricated with such smallcell sizes that they do not allow optional reinforcement materialparticles to migrate into the voids defined by the pores in the foammatrix material.

Vibration may be used to increase the packing efficiency of the foammatrix material 130 (e.g., to pack optional reinforcement material(s) orthe binder material within the structure of a foam matrix material). Inan example, after the foam matrix material 130 has been added to themold assembly 100, the structural element metal blank 36 may then beplaced within the mold assembly 100. In one or all examples, the foammatrix material 130 may be designed to have inserts for placing themetal blank 36. The metal blank 36 preferably includes inside diameter37, which is larger than the outside diameter 154 of sand core 150.Additional foam matrix material 130 may be added to a desired levelwithin the cavity 104, which may be designed to a specific shape forinclusion therein.

As illustrated, binder material 160 may be placed on top of the foammatrix material 130, metal blank 36, and core 150. Alternatively, thebinder material 160 may be included with at least a portion of the foammatrix material 130. The binder material 160 may be covered with a fluxlayer (not expressly shown). Alternatively, a binder material 160 bowl(not expressly shown) disposed at the top of the funnel 120 may be usedto contain the binder material 160, which, during infiltration, willthen flow down into the foam matrix material 130, which may or may notinclude optional reinforcement material. In alternative examples, thebinder material 160 includes optional reinforcement material (e.g.,particulate powder tungsten carbide), regardless of whether the foammatrix material 130 includes such optional materials, without departingfrom the scope of the present disclosure.

A cover or lid (not expressly shown) may be placed over the moldassembly 100. The mold assembly 100 and materials disposed therein maythen be preheated and then placed in a furnace, or directly placed in afurnace. When the furnace temperature reaches or optionally exceeds themelting point of the binder material 160, the binder material 160 mayliquefy and infiltrate the foam matrix material 130, binding the foammatrix material 130 to the various structural elements.

After a predetermined amount of time allotted for the liquefied bindermaterial 160 to infiltrate the foam matrix material 130, the moldassembly 100 may then be removed from the furnace and cooled at acontrolled rate. Once cooled, the mold assembly 100 may be broken awayto expose the bit body having a structural MMC comprising a foam matrixmaterial, a binder material, various structural elements, and anyoptional reinforcement material. Subsequent processing and machining,according to well-known techniques, may be used to, produce a drill bithaving the desired bit body, if necessary.

The structural MMC portion may be homogeneous throughout orheterogeneous throughout the bit body as illustrated in FIGS. 2-3.

In an example, the structural MMC portion may be localized within aportion of the bit body with the remaining portion being formed by ahard composite that is not a structural MMC. In some instances,localization may provide mitigation for crack initiation and propagationwhile minimizing the additional cost that may be associated with somestructural MMC materials and/or processing. Further, the inclusion ofthe foam matrix material in the bit body may, in some instances, reduceerosion properties of the bit body because of the lower concentration ofreinforcing particles. Therefore, in some instances, localization of thefoam matrix material to only a portion of the bit body may mitigate anyreduction in erosion properties thereat.

For example, FIG. 6 is a cross-sectional view showing one example of adrill bit 20 formed with a bit body 50 having a hard composite portion132 that is not a structural MMC in combination with one or morestructural MMC portions 131 (two shown) in accordance with the teachingsof the present disclosure. The structural MMC portions 131 are shown tobe located proximal to the nozzle openings 54 and an apex 64, twostructural element areas of bit bodies that typically have an increasedpropensity for cracking. As used herein, the term “apex,” andgrammatical variants thereof, refers to the central portion of theexterior surface of the bit body that engages the formation duringdrilling. Typically, the apex of a drill bit is located at or proximalto where the blades 52 (FIG. 3) meet on the exterior surface of the bitbody that engages the formation during drilling.

In another example, FIG. 7 is a cross-sectional view showing one exampleof a drill bit 20 formed with a bit body 50 having a hard compositeportion 132 and a structural MMC portion 131 in accordance with theteachings of the present disclosure. The structural MMC portion 131 isshown to be located proximal to the nozzle openings 54 and the pockets58.

In some examples, the configuration of the foam matrix material (e.g.,shape, cell type, cell size, cell shape, foam material, and the like)may be different in different portions of the structural MMC 131 toachieve different qualitative results, such as to mitigate crackinitiation and propagation, mitigate erosion, and/or minimize theadditional cost that may be associated with some foam matrix materials.

For example, FIG. 8 is a cross-sectional view showing one example of adrill bit 20 formed with a bit body 50 having a structural MMC portion131 in accordance with the teachings of the present disclosure. The cellsize of the foam matrix material decreases or progressively decreasesfrom apex to the shank of the bit body 50 (as illustrated by the degreeor concentration of stippling in the bit body 50). As illustrated, thesmallest cell sizes of the foam matrix material are adjacent the nozzleopenings 54 and the pockets 58 of the structural MMC 131 and the largestcell sizes of the foam matrix material are adjacent the metal blank 36of the structural MMC 131.

In some instances, the concentration change of the cell sizes of a foammatrix material (or multiple foam matrix materials) of a structural MMCmay be gradual. Alternatively, the concentration change may be moredistinct and resemble layering or localization. For example, FIG. 9 is across-sectional view showing one example of a drill bit 20 formed with abit body 50 having a hard composite portion 132 that is not a structuralMMC and a structural MMC portion 131 in accordance with the teachings ofthe present disclosure. The structural MMC portion 131 is shown to belocated proximal to the nozzle openings 54 and the pockets 58 in layers131 a, 131 b, and 131 c. The layer 131 a is shown to be located proximalto the nozzle openings 54 and the pockets 58 and may have the smallestcell sizes of a foam matrix material. The layer 131 c with the largestcell sizes of a foam matrix material is shown to be located proximal tothe hard composite portion 132. The layer 131 b with the intermediatecell sizes of the foam matrix material is shown to be disposed betweenlayers 131 a and 131 c. It is to be appreciated that the layers 131 a,131 b, and 131 c may be made of the same or different material, and maybe a continuous or discontinuous foam matrix material. Alternatively oradditionally, the structural MMC 131 portion of layers 131 a, 131 b, and131 c may vary by the type of material forming the foam matrix material,the cell shape, the cell type, the foam matrix material shape, and thelike, without departing from the scope of the present disclosure.

One skilled in the art would recognize the various configurations andlocations for the hard composite portions that are not structural MMCsand the structural MMC portions (including with varying configurationsthereof) that would be suitable for producing a particular tool, orwellbore tool, such as a bit body and a resultant drill bit to achievecertain qualities, such as a reduced propensity to have cracks initiateand propagate.

Further, one skilled in the art would recognize the modifications to thecomposition of the reinforcement material 130 of FIG. 5 to form a bitbody according to the above examples in FIGS. 6-9 and otherconfigurations within the scope of the present disclosure.

FIG. 10 is a schematic showing one example of a drilling assembly 200suitable for use in conjunction with the drill bits of the presentdisclosure. It should be noted that while FIG. 10 generally depicts aland-based drilling assembly, those skilled in the art will readilyrecognize that the principles described herein are equally applicable tosubsea drilling operations that employ floating or sea-based platformsand rigs, without departing from the scope of the disclosure.

The drilling assembly 200 may include a drilling platform 202 coupled toa drill string 204. The drill string 204 may include, but is not limitedto, drill pipe and coiled tubing, as generally known to those skilled inthe art. A drill bit 206 according to any of the examples describedherein may be attached to the distal end of the drill string 204 and maybe driven either by a downhole motor and/or via rotation of the drillstring 204 from the well surface. As the drill bit 206 rotates, itcreates a wellbore 208 that penetrates the subterranean formation 210.The drilling assembly 200 may also include a pump 212 that circulates adrilling fluid through the drill string (as illustrated as flow arrowsC) and other pipes 214.

One skilled in the art would recognize other equipment suitable for usein conjunction with drilling assembly 200, which may include, but is notlimited to, retention pits, mixers, shakers (e.g., shale shaker),centrifuges, hydrocyclones, separators (including magnetic andelectrical separators), desilters, desanders, filters (e.g.,diatomaceous earth filters), heat exchangers, any fluid reclamationequipment, and the like. Further, the drilling assembly may include oneor more sensors, gauges, pumps, compressors, and the like.

The structural MMC portion comprising foam matrix material infiltratedwith a binder material(s) described herein may be implemented in othertools or wellbore tools or portions thereof and systems relatingthereto, without departing from the scope of the present disclosure.Examples of such wellbore tools where a structural MMC portion describedherein may be implemented in at least a portion thereof may include, butare not limited to, reamers, coring bits, rotary cone drill bits,centralizers, pads used in conjunction with formation evaluation (e.g.,in conjunction with logging tools), packers, and the like. In someinstances, portions of wellbore tools where a structural MMC describedherein may be implemented may include, but are not limited to, wearpads, inlay segments, cutters, fluid ports (e.g., the nozzle openingsdescribed herein), convergence points within the wellbore tool (e.g.,the apex described herein), and the like, and any combination thereof.

Examples disclosed herein include:

Example A: A structural metal-matrix composite (MMC) comprising: a foammatrix material having a cellular structure, the foam matrix materialselected from the group consisting of a metallic foam, a ceramic foam,and any combination thereof; a structural element of a tool; and abinder material infiltrated through the cellular structure of the foammatrix material to bind the foam matrix material and the structuralelement of the tool.

Example B: A method comprising: placing a foam matrix material in aregion of a mold, the foam matrix material having a cellular structureand selected from the group consisting of a metallic foam, a ceramicfoam, and any combination thereof; placing a binder material in themold; placing a structural element of a tool in the mold; heating themold, the foam matrix material, the binder material, and the structuralelement of the tool to a temperature above the melting point of thebinder material; infiltrating the cellular structure of the foam matrixmaterial with the binder material; and cooling the mold, the foam matrixmaterial, the binder material, and the structural element of the tool,wherein the infiltrated binder material binds the foam matrix materialand the structural element of the tool.

Example C: A drilling assembly comprising: a drill string extendablefrom a drilling platform and into a wellbore; a drill bit attached to anend of the drill string and including a bit body and a plurality ofcutting elements coupled to an exterior portion of the bit body, the bitbody composed of a structural metal-matrix composite (MMC) comprising: afoam matrix material having a cellular structure, the foam matrixmaterial selected from the group consisting of a metallic foam, aceramic foam, and any combination thereof; the bit body; and a bindermaterial infiltrated through the cellular structure of the foam matrixmaterial to bind the foam matrix material and the bit body; and a pumpfluidly connected to the drill string and configured to circulate adrilling fluid to the drill bit through the wellbore.

Exemplary additional elements applicable to A, B, and/or C may includethe following in any suitable combination:

Element 1: Wherein the cellular structure of the foam matrix material isan open-cell foam structure or a closed-cell foam structure.

Element 2: Wherein the structural MMC further comprises reinforcementparticulates.

Element 3: Wherein the foam matrix material comprises the metallic foamcomposed of a metallic material selected from the group consisting of ametal, a metal alloy, a metal carbide, a superalloy, and any combinationthereof.

Element 4: Wherein the foam matrix material comprises the ceramic foamcomposed of a ceramic material selected from the group consisting of anoxide ceramic, a boride ceramic, a nitride ceramic, a silicate ceramic,a carbide ceramic, diamond, and any combination thereof.

Element 5: Wherein the binder material is at least partially selectedfrom the group consisting of copper, nickel, manganese, zinc, and anycombination thereof.

Element 6: Wherein the structural element of the tool corresponds to aportion of a wellbore tool.

Element 7: Wherein the structural element of the tool corresponds to abit body of a drill bit.

Element 8: Wherein the foam matrix material melts into, dissolves into,diffuses into, or reacts with the binder material during infiltration ofthe foam matrix material with the binder material, thereby forming anetworked ductile phase.

Element 9: Wherein the foam matrix material reacts with the bindermaterial during infiltration of the foam matrix material with the bindermaterial, thereby forming an intermetallic phase.

Element 10: Wherein a mold is used to form a structural metal-matrixcomposite, and the mold corresponds to all or a portion of a wellboretool mold.

Element 11: Wherein a mold is used to form a structural metal-matrixcomposite, wherein the mold corresponds to all or a portion of a drillbit.

Element 12: Wherein a mold is used to form a structural metal-matrixcomposite, wherein the mold corresponds to a bit body of a drill bit.

By way of non-limiting example, exemplary combinations applicable to A,B, and C include: 1-12; 1, 3, and 10; 4, 5, 7, and 12; 8 and 9; 2, 4,11, and 12; 6 and 7; 8, 9, and 11; and the like.

One or more illustrative examples are presented herein. Not all featuresof a physical implementation are described or shown in this applicationfor the sake of clarity. It is understood that in the development of aphysical embodiment incorporating the examples described herein,numerous implementation-specific decisions must be made to achieve thedeveloper's goals, such as compliance with system-related,business-related, government-related and other constraints, which varyby implementation and from time to time. While a developer's effortsmight be time-consuming, such efforts would be, nevertheless, a routineundertaking for those of ordinary skill in the art and having benefit ofthis disclosure.

Therefore, the present disclosure is well adapted to attain the ends andadvantages mentioned as well as those that are inherent therein. Theparticular examples disclosed above are illustrative only, as thepresent disclosure may be modified and practiced in different butequivalent manners apparent to those skilled in the art having thebenefit of the teachings herein. Furthermore, no limitations areintended to the details of construction or design herein shown, otherthan as described in the claims below. It is therefore evident that theparticular illustrative examples disclosed above may be altered,combined, or modified and all such variations are considered within thescope and spirit of the present disclosure. The examples illustrativelydisclosed herein suitably may be practiced in the absence of any elementthat is not specifically disclosed herein and/or any optional elementdisclosed herein. While compositions and methods are described in termsof “comprising,” “containing,” or “including” various components orsteps, the compositions and methods can also “consist essentially of” or“consist of” the various components and steps. Also, the terms in theclaims have their plain, ordinary meaning unless otherwise explicitlyand clearly defined by the patentee. Moreover, the indefinite articles“a” or “an,” as used in the claims, are defined herein to mean one ormore than one of the element that it introduces. If there is anyconflict in the usages of a word or term in this specification and oneor more patent or other documents that may be incorporated herein byreference, the definitions that are consistent with this specificationshould be adopted.

What is claimed is:
 1. A structural metal-matrix composite (MMC)comprising: a foam matrix material having a cellular structure, the foammatrix material selected from the group consisting of a metallic foam, aceramic foam, and any combination thereof; a structural element of atool; and a binder material infiltrated through the cellular structureof the foam matrix material to bind the foam matrix material and thestructural element of the tool.
 2. The structural MMC of claim 1,wherein the cellular structure of the foam matrix material is anopen-cell foam structure or a closed-cell foam structure.
 3. Thestructural MMC of claim 1, wherein the foam matrix material comprisesthe metallic foam composed of a metallic material selected from thegroup consisting of a metal, a metal alloy, a metal carbide, asuperalloy, and any combination thereof.
 4. The structural MMC of claim1, wherein the foam matrix material comprises the ceramic foam composedof a ceramic material selected from the group consisting of an oxideceramic, a boride ceramic, a nitride ceramic, a silicate ceramic, acarbide ceramic, diamond, and any combination thereof.
 5. The structuralMMC of claim 1, wherein the structural MMC further comprisesreinforcement particulates.
 6. The structural MMC of claim 1, whereinthe binder material is at least partially selected from the groupconsisting of copper, nickel, manganese, zinc, and any combinationthereof.
 7. The structural MMC of claim 1, wherein the structuralelement of the tool corresponds to a portion of a wellbore tool.
 8. Thestructural MMC of claim 1, wherein the structural element of the toolcorresponds to a bit body of a drill bit.
 9. A method comprising:placing a foam matrix material in a region of a mold, the foam matrixmaterial having a cellular structure and selected from the groupconsisting of a metallic foam, a ceramic foam, and any combinationthereof; placing a binder material in the mold; placing a structuralelement of a tool in the mold; heating the mold, the foam matrixmaterial, the binder material, and the structural element of the tool toa temperature above the melting point of the binder material;infiltrating the cellular structure of the foam matrix material with thebinder material; and cooling the mold, the foam matrix material, thebinder material, and the structural element of the tool, wherein theinfiltrated binder material binds the foam matrix material and thestructural element of the tool.
 10. The method of claim 9, wherein thecellular structure of the foam matrix material is an open-cell foamstructure or a closed-cell foam structure.
 11. The method of claim 9,wherein the structural MMC further comprises reinforcement particulates.12. The method of claim 9, wherein the foam matrix material melts into,dissolves into, diffuses into, or reacts with the binder material duringinfiltration of the foam matrix material with the binder material,thereby forming a networked ductile phase.
 13. The method of claim 9,wherein the foam matrix material reacts with the binder material duringinfiltration of the foam matrix material with the binder material,thereby forming an intermetallic phase.
 14. The method of claim 9,wherein the mold corresponds to all or a portion of a wellbore toolmold.
 15. The method of claim 9, wherein the mold corresponds to all ora portion of a drill bit.
 16. The method of claim 9, wherein the moldcorresponds to a bit body of a drill bit.
 17. A drilling assemblycomprising: a drill string extendable from a drilling platform and intoa wellbore; a drill bit attached to an end of the drill string andincluding a bit body and a plurality of cutting elements coupled to anexterior portion of the bit body, the bit body composed of a structuralmetal-matrix composite (MMC) comprising: a foam matrix material having acellular structure, the foam matrix material selected from the groupconsisting of a metallic foam, a ceramic foam, and any combinationthereof; the bit body; and a binder material infiltrated through thecellular structure of the foam matrix material to bind the foam matrixmaterial and the bit body; and a pump fluidly connected to the drillstring and configured to circulate a drilling fluid to the drill bitthrough the wellbore.
 18. The drilling assembly of claim 17, wherein thecellular structure of the foam matrix material is an open-cell foamstructure or a closed-cell foam structure.
 19. The drilling assembly ofclaim 17, wherein the foam matrix material comprises the metallic foamcomposed of a metallic material selected from the group consisting of ametal, a metal alloy, a metal carbide, a superalloy, and any combinationthereof.
 20. The drilling assembly of claim 17, wherein the foam matrixmaterial comprises the ceramic foam composed of a ceramic materialselected from the group consisting of an oxide ceramic, a borideceramic, a nitride ceramic, a silicate ceramic, a carbide ceramic,diamond, and any combination thereof.